As a background art of the present technical field, there is an uncapping device including a mechanism for sucking and capturing a particle of JP 2014-1926 A (PTL 1). The uncapping device described in PTL 1 includes partition plates for covering the circumference of a sample container transferred, container gripping mechanisms that fix the sample container in a pinching manner and has an air intake function for sucking air around the sample container by means of power of an exhaust fan connected via a pipe, and an uncapping mechanism having a discharge function that removes a cap attached to the sample container and discharges air by means of power of a discharge fan connected to the circumference of the sample container via a pipe. With this apparatus, an airborne material, e.g., mist, is sucked to the container gripping mechanisms by an airflow generated between the uncapping mechanism and the container gripping mechanisms so that a micro-level airborne material, e.g., dirt and mist floating in the atmosphere, do not enter the uncapped sample container. Furthermore, the exhaust fan includes a filter on the suction side so that an airborne material, e.g., sucked mist, is not discharged through the exhaust fan.